Nitroglycerine explosive



Patented Nov. 7, 1922.

UNlTED STATES PATENT crates.

CLIFFORD A. WOODBURY, 01 MEDIA, PENNSYLVANIA, ASSIGNOR TO E. I. DU PONT DE NEMOURS & COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELA' WARE,

No-Drawing. Application filed March 9,

To all whom it may concern:

Be it known that I, CLIFFORD A. Woon- BURY, a citizen of the United States, and a resident of Media, in the county of Delaware 5 and State of Pennsylvania, have invented certain new and useful Nitroglycerine Explosives, of which the following is a specification.

My invention relates to nitroglycerine ex- 'plosives and comprises explosives of this kind containing ammonium perchlora Dynamites containing nitroglycerine, through continued use over a long period of time, have become recognized as standards inthe ,dynamite industry and in spite of the many new explosives developed, have maintained their leadership.' Among the several reasons for this, the most important is undoubtedly the surety of action. inherent in '20 a nitroglycerine dynamite. This suretyis brought about through the sensitiveness of the nitroglycerine which is such as to be little altered by factors whigh tend to lower sensitiveness. Dynamites not containing "nitroglycerine are at best inclined to be rather insensiti e to detonation by means of blasting caps, and are easily rendered too insensitive for practical use by influences which have no serious effect on nitroglycer- 80 inc dynamites.

. Dynamites containing though of extended use, have always hac certain undesirable properties. Among these, the more important are high .sensitiveness.

95 to shock, ease of ignition, and tendency to exude nitroglycerine particularly in the case of high strength explosives where a high percentage of nitroglycerihe must be used. Furthermore, with high strength nitro- 40 glycerine dynamites it is impracticable to supply the necessary oxygen for the combustible absorbent on account of the high percentage of absorbent that has to be used in order to properly hold all of the niro glycerine. This leads to the production of noxious gaseson explosion, thus seriously affecting the use of such explosive in underground work.

Glycerine, from which nitroglycerine is .553 made, is obtained as a by-product in the manufacture of soap, and the quantities produced are very limited in comparison wit the demand for explosives using nitroglycerine.

H5 Many elicit have een made to find nitroglycerine,

NITROGLYCERINE EXPLOSIVE.

1920. Serial No. 864,396.

stitutes for nitroglycerine in dynamites and the most successful have been along the lines of utilizing ammonium nitrate to replace a portion of the nitroglycerine. Such exploslves are much safer than straight nitro 6 0 glycerine dynamites due to being much less sensitive to shock and far more difficult to lgnlte. On the other hand, ammonium nitrate explosives are extremely hygroscopic, absorbing moisture so rapidly that they becomeunfit for use when stored for any appreciable length of time in humid climates. Furthermore, due to the peculiar habit of am n onlum mtrate to change its crystalline form at about 90 R, such explosives have a great tendency to set extremely hard when stored in climates where the temperature at times reaches or exceeds 90 F.

I have discovered that the substitution of ammonium perchlorate for a portion of the 75 mtroglycerine in dynamites containing nitroglycerine results in explosives much less in- I flammable and less sensitive .to shock, but still retaining in a-large measure the surety of detonation and propagation and the low hygroscopicity inherent in straight nitroglycerine dynamites. In other words, the substitution of ammonium perchlorate for a portion of the nitroglycerine improves the explosive from the point of view of safety in a manner similar to improvement 0b l tained by using ammonium nitrate, without introducing such undesirable properties as excessive hygroscopicity and tendency to set hard during storage. Furthermore, it is practicable to replace a much greater proportion of nitroglycerine when usingammonium perchlorate than is the case when using ammonium nitrate, due to the fact that the former does not decrease the sensitiveness to detonation and propagation to nearly so great an extent as is true with the latter.

For example, I have found that an explosive containing 10 parts of nitroglycerine and 30 parts of ammonium perchlorate exhibits an ability to propagate detonation almost exactly equal to that exhibited by an explosive containing 20 parts of nitroglycerme and 28 parts of ammonium nitrate.

Another important feature of my invenh tion is that by, substituting ammonium perchlorate for a portion of the nitroglycerine there can be produced high grade nitpgglyqepige dynamites free from a-tend- 11 ency to exude nitroglycerine and so balanced as to oxygen content as to give unobjectionable gases on explosion. In underground work involving the blasting of hard rock, explosives of the so-called gelatine type are used almost to the exclusion of all other types. These explosives are comprised of nitroglycerine gelatinized with a small percentage of nitroc'otton and absorbed or mixed with various materials such as alkalimetal nitrates, non-explosive absorbents, for example Wood pulp, etc. Under present circumstances there is a rather low limit to the percentage of nitroglycerine which can be used in such explosives and still retain a favorableoxygen balance, due to the high percentage of carbonaceous material, such as wood pulp, which has to be used in order to avoid exudation of the nitroglycerine. A portion of the nitroglycerine can, it is true, be replaced by ammonium nitrate and a proper oxygen balance of the explosive it" self thereby obtained; but this introduces another complicating factor, for, due to the hygroscopicity' of the nitrate of ammonia, it is necessary to give further protection to the explosive by coating it with an extra quantity of waterproofing material such as parafiine, and, inasmuch as the parafiine is consumed in the explosion, the oxygen balance of the explosive is thereby upset, with the result that excessive quantities of carbon monoxide are formed. On account of the low hygroscopicity of ammonium perchlorate, it is not necessary to use an extra amount of paraffine, thereby: making possible the manufacture of high grade gela tine dynamites of the proper oxygen balance for underground work.

Examples of gelatine dynamites with and without ammonium perchlorate are:

(that is, the proportion of oxygen above that required to combine with all the carbon and hydrogen present to form CO and H 0.)

Though I have described the use of ammonium perchlorate in nitroglycerine explosives, I'do not wish to confine myself to explosives in which the liquid explosive in gredient is comprised solely of this material. As a matter of fact I prefer to use liquids composed of nitroglycerine in which is dissolved other compounds useful for depressing or retarding the freezing of the nitroglycerine, for example, aromatic nitro compounds, nitrated sugars, nitrated polymerized glycerine, etc. The nitrated polymerized glycerine is nitrated diglycerol; both. the nitratcdsugar and the nitrated polymerized glycerol may therefore be referred to as. a nitrate of an aliphatic compound having at least 6 and at most 12 carbon atoms and at least 4: hydroxy groups.

As typical examples of these new explosives I give the following:

III. IV. V. VI. VII. VIII.

Nitroglycerine 8 6. 5 40 32 28 Nitrated sugar... 1. 5 4 Nitro aromatic (TNT). 2 2 S 8 Ammonium perchlorate. 30 80 27 27 27 Sodium nitrate 42 43 22 2O Carbonmeous material. 17 16 12 10 12 Chalk 1 1 1 1 1 1 IX. X. XI. XII. XIII. XIV.

Nitroglyceriue. 20 18 25 20 18 Nitrated polym-dzed glycerlne 5 4 5 4 Nitro aromatics 3 3 Niti'ocotmn (l. 6 0. 6 0.6 0.6 0.6 0.6 Ammonium pen a 1 30 30 10 10 10 Sodium nitrate 22 22 24 48 48 48 carbonaceous com. ustible... 21.4 21.4 19.4 15.4 15. 4 15. 4 hall: 1 1 1 1 l 1 range of proportions in which the several ingredients may be used. In general I consider it desirable to have nitroglycerine prescut to the extent of at least 5%, and to have ammonium perchlorate present in the proportions of from about 10 to based on the total weight of the dynamite. The proportion of carbonaceous material which I prefer lies between 8 and, 25%, and that of the alkali metal nitrate, between 15 and 45%. Although from 10 to 35% of ammonium perchlorate will ordinarily" be sufficient, a much greater proportion, for instance up to 65%, may be used upon occasion.

I claim:

1. A dynamite comprising nm'oglycerine, from about 10 to 35% of ammon um perchlorate, and a carbonaceous combustible material.

2. A dynamite comprising from 6.5 to 40% of nitroglycerine, from about 10 to 35% of ammonium perchlorate, and a carbonaceous combustible material.

A. dynamite comprising at least. 5 parts m1 abo (iiisoia'h and pari's Di :1 amiimnacoolis a1; material. 10. oxpiosive comprising nitroglycer- -1. A. dyii 'niie eomprising from 6.5 to 40 ine,ii1 which nitrated polymerized glycerine parts of nita'ogiy fei'ine dissolved ammonium perch oiateq and a,

kaibmetoi niira te, and from. about 8 to 25 of a carbonaceous, non-explosive mm parts of ammo! 121m pfii'cili-o' i.

25 parts of camoniiceous auto about 2' mm.

11. explosive, comprising at ieast 5% of niiiiogiycerine, in which 'nit'ated polyo ex'izeo is dissolved, ammonium perciiim'ate, an aliiaikmotu nitrate, and a oarbonnceous, non-explosive material,

nir ggiy m1-i" dynamite n 7 12. in oxpiosivo compi'ismgz from 6.5 to snfiiment mnonnt m ammonium porcn. rate Q) parts of mtrogyicerinei in which niti'nted. to ronsier the oxygen (outwitof the ri mw polyznerlzed gyicei'm-s 1S dissoiv-eii, from mite greater than requneil to Qombm? about 10 to 35 parts of ammonium perchk with ali the czufihon and i 245912 pr'sent to from about to parts of an alkali- (-(a Na U P Y 1' 4') 1 b V w mun all L 1.1mm iildihij. am mom 2 out 8 to, pans To An up! I of a carbonaceou, non-xploslve material.

in whim as, nil. )iosive comprising nitroglycerhaving at- 1911;? i p poiymerizerl gylcerine, amino- 21011S21Hil m. 1921? "n perchlom'bfi, an alkali-metal nitrate,

and :1 mrbonacoons. non-explosive material. i. A dynamite comprising at least 5% of 8. sin .1 i l i- :giycerine, from about 10h) of am- HOi-IOgiYCQI'HiG, m Wmcn i i monmm perchlorate, from about 15 to 45% phatii: compound having :1? i911 and a of an aikzfii-me'al nitrate, a carbonaceousmost 12 carbon atoms an noi'i-expioswe nmtoriaL md a mtruize of an groups is dissoivozi ammaliphatic oom wmd llHVHlg at 1938b 6 and at alkali-meld nits: moat 12 carbon atoms and at least 4; hydrozzy non-explosive zzmteriai. groups.

9. Em expiosiva cf A fiyfiallll lfi 01 time composition ei parts nimogi meri @111 aiipimtic (-ompomid at most carbon moms (i1OX} groups ii$soivo i fir 5 35 parts aiiinlonium (15th in Claim M mid -containing from to of mtrogyicerme.

:Ji. WOGDBURY.

It is hereby ceii ifisci that in Letters Fm'iezlt 7, 1591 upon 3, line claim 8 for thesz w'aglgc'omw, and line claim ii 501 M v I in tesumony whereof i my siggatnre. 

